LOS ANGELES  A wildfire threatening thousands of homes in Southern California spread slowly through scenic canyonlands Saturday, straining resources as crews struggled to contain hundreds of other blazes around the state.

"The firefighters are stretched thin, they are exhausted," and some have gone days without sleep, said Gov. Arnold Schwarzenegger, who visited a command post in Santa Barbara County.

A slew of wildfires, most ignited by lightning two weeks ago, has burned more than 800 square miles throughout California. The blazes have destroyed at least 69 homes and other buildings and contributed to the death of a firefighter who suffered a heart attack while digging fire lines.

About 1,400 fires have been contained, but more than 330 still burned out of control Saturday.

Schwarzenegger said the state's top priority was in the coastal region of Santa Barbara County, where nearly 2,700 homes were threatened by a four-day-old fire in the Los Padres National Forest that has burned about 13 square miles.

Cooler, moist air Saturday morning kept the fire sluggish and helped firefighters trying to surround it, said Pat Wheatley, county spokeswoman. The fire was 24 percent contained, she said.

"It's just spreading in each direction, but they are holding the line beautifully," she said.

Crews hoped to make more progress before the return of late afternoon "sundowner" winds that on Friday evening sent flames racing up to homes.

More than 2,600 homes were under mandatory evacuation Saturday, and residents in another 1,400 were warned to be ready to flee if the flames gathered speed.

Wheatley said about 4,000 homes were under a warning Saturday afternoon  a situation not as urgent as a mandatory evacuation  in four canyons at the northern end of the blaze.

The fire, which was burning in 15-foot-high, half-century-old chaparral, had the potential to roll through a hilly area of ranches, housing tracts and orchards between the town of Goleta and Santa Barbara.

"The advice is that you get prepared, that you get your belongings together and you stay very watchful," Wheatley said.

Temperatures were expected to reach the high 80s, and the smoke from the fire made for bad air quality.

Nearly 1,200 firefighters struggled to surround the blaze while a DC-10 air tanker and other aircraft dumped water and fire retardant along ridges and in steep canyons.

Investigators think the fire, which began Tuesday, was human-caused. The U.S. Forest Service on Saturday asked for public help in determining who set it and whether it was sparked accidentally or on purpose.

Meanwhile, cooler weather helped crews attacking a two-week-old blaze that has destroyed 22 homes in Big Sur, at the northern end of the Los Padres forest.

The fire, which had blackened more than 110 square miles, was only 5 percent contained, but morning fog that moved in from the sea helped prevent it from advancing on Big Sur's famed restaurants and hotels.

"We're gaining ground, but we're nowhere near being done," said Gregg DeNitto, a spokesman for the U.S. Forest Service. "There's still a lot of potential out there. The fire has been less active the last couple of days. We've had favorable weather; they are taking every opportunity to get some line on it."

But the weather was expected to become hotter and drier over the next couple of days, he said, with winds and temperatures rising and humidity dropping.

"The fire still has the potential for movement and the potential to get out of our containment lines," he said.

A homeowner near Big Sur was arrested Friday after officials said he refused orders to stop setting his own backfires.

The governor said that he recently ordered 400 National Guard troops to be trained in wildfire fighting so they could help fight the state's blazes. He also urged lawmakers to adopt his budget plan for a $70 million emergency surcharge on home and business insurance policies to buy more firefighting equipment.

California now has a year-round fire season and needs the money from the fee, which should cost the average homeowner about $1 a month, Schwarzenegger said.